What Is Ulcerative Colitis?

Ulcerative colitis is a chronic (long-term) inflammatory disease. It affects the lining of the large intestine, or colon, and rectum. The rectum is the last section of the colon and is located just above the anus. People with ulcerative colitis have tiny ulcers and abscesses in their colon and rectum. These flare up periodically and cause
bloody stools and diarrhea. Ulcerative colitis may also cause severe
abdominal pain and anemia. Anemia is marked by low levels of healthy red blood cells.

Ulcerative colitis has alternating periods of flare-ups and remission. During remission the disease seems to have disappeared. The periods of remission can last from weeks to years.

The inflammation usually begins in the rectum. It then spreads to other segments of the colon. How much of the colon is affected varies from person to person. If the inflammation is limited to the rectum, the disease is called ulcerative proctitis.

How Is Ulcerative Colitis Diagnosed?

Ulcerative colitis closely resembles Crohn's disease. Crohn's is another inflammatory bowel disease. Often the only thing that distinguishes ulcerative colitis is that it affects only the colon. Crohn's may affect any part of the digestive system, including the mouth. Crohn's disease also is particularly destructive to the small intestine, known as the ileum.

A doctor may order several different types of tests when considering ulcerative colitis as a diagnosis. These include: